Manufacture of cables



May 22, 1934. E HAETTNER 1,959,471

MANUFACTURE OF CABLE 5 Filed March 26, 1931 .2 Sheets-Sheet l [N VeNT'b pg May 22, 1934. A, E, HAETT ER 1,959,471

MANUFACTURE OF CABLES I Filed March 26, 1951 2 Sheets-Sheet 2 AYAVAYAVAVAIA.\

/ ve v To i l atented May 22, I934 1,959,472 MANUFACTURE OF CABLEQ Axel Erik Haettner; Appelviken, Sweden, assignor to Telefonaktiebolaget L. M. Ericsson, Stockholm, Sweden, a. registered company of Sweden Application March 26,

1931, Serial No. 525,508

In Sweden April 1, 1930 13- Claims.

The manufacture of cables having twisted conductor branches has hitherto not been sufl'lciently accurate to assure the desired properties in the ready made cable in regard to mutual coupling between the branches caused by capacity and inductance. For example in telephone cables it is desirable to so adjust said coupling between the line branches that cross talk between different talking lines is eliminated. To avoid or at least to reduce such cross talk as far as possible compensating condensers have generally been included in the manufactured cable or the mutual positions of the branches shifted in the cable joints. It has also been proposed to change the mutual positions of the line branches by mechanical dispositions in the twisted cable so as to obtain the wanted compensation.

The present invention has for its object a manufacturing method whereby inaccuracies in the manufacture may be compensated already during the manufacturing process so that the ready twisted cable obtains the wanted electrical prop erties. The invention consists substantially therein that during the twisting operation the portions of the cable branches being subjected to the twisting are positively guided or otherwise actuated whereby the branches in the ready twisted cable are brought to change their mutual positions in correspondence with the fluctuations of the mutual coupling between the line branches as ascertained by measurement.

The invention will'be more closely described with reference to the accompanying drawings. Figure 1 shows diagrammatically, and partially in perspective view an embodiment of a device according to the invention. Figure 2 is a detail of Figure 1 in plan view. Figure 3 is a circuit diagram showing a method for automatic compensation.

The arrangement shown in Figures 1 and 2 is particularly applicable to a quad twisted cable the line branches 1, 2, 3, 4 of which during the twisting procedure are wound off from rolls 5, 6, 7, 8 and in twisted condition are wound ona cable reel 9. The line branches pass through guide holes in a stationary guide plate 10 and converge towards a nipple 11 through which the cable 12 passes in twisted condition. In the shown example the rolls 5, 6, 7, 8 are stationary journalled whereas the cable reel 9 is adapted to rotate about the axis of the cable 12. The wires are on the one side connected to the corner points 21, 22, 23, 24 of a Wheatstones bridge D through sliding contacts 13,14, 15, 16 whereas the opposite ends are each connected to one terminal 17, 18, 19, 2 0

(CL Nil-78) of the reel 9 and electrically insulated from each other. The four different links in said bridge include condensers C13, C14, C24 and C23. Between the points 21 and 22 an alternating current source 25 having a transformer 26 is connected up. Between the points 23, 24' a telephone receiver 27 is connected up together with its appertaining transformer 28. To the latter point of the bridge also the two stationary plates 29, 30 of a balance condenser K are connected the rotatable plate 31 of said condenser being connected to the point 21.

The parts of the wires 1, 2, 3, 4 being twisted are in the shown example adapted to be actuated by means of two devices A, B resembling shears the pivots 32, 33 of which are journalled in stationary bearings and of which the legs 34 and 35 at their outer ends carry rolls 36 and B'Trespec tively. The shape and disposition of said rolls is easily understood by Figure 2. Each roll is adapted to actuate one pair. of wires the rolls then, on account of their shape being contracted towards the ends, pressing the two wires in the ape pertaining pair of wires inwards and also in lateral direction so that the distance between the wires is increased. The two rolls in each device A, B are disposed on opposite sides of the wire bundle so that, upon actuating one device A, B, the rolls bring the appertaining wire pairs to wards each other while at the same time the wires within each of said wire pair are removed from eachother. The legs 34, 35 of the devices A, B are connected with lines 40, 41 by means of links 38, 39 which lines over guide rolls 42, 43 extend to operating members 44, 45, each consisting of a drum 46, 47 at which the line is fixed and whereon it may be wound, and to handles 48, 49 by means of which the drum may be rotated the angular displacement being read off on a scale 50 and 51 respectively. Helical springs 54, 55 disposedbetween the junction points 52, 53 of the links 38, 39 and the pivots 32, 33 tend to bring the rolls 36, 3'7 normally out of engagement with the wires.

Ifthe condensers C13, C14, C24, C23 are assumed to represent the capacities between the corresponding line branches the condition for a complete balancing of the cable properties may be expressed by the equation When this condition is complied with and the balance condenser K takes up its middle position consequently no current will pass through the telephone receiver 27. If, however, the balance during the twisting procedure is disturbed by any inaccuracy in the twisting this fact is indie cated by a sound in the telephone receiver 27. Such a disturbance of the balance may now according to the invention be compensated during the twisting operation by actuating the wires by means of the devices A, B. By actuating for example the member A the capacity between the wires 1 and 3 or 2 and 4 respectively is thus increased whereas simultaneously the capacity between the wires 1 and 4 or 2 and 3 respectively is reduced, which fact in the above equation corresponds to an increased value of the terms C13+C24 and a reduction in the valueof the terms 0144-023. With the aid of the device B an opposite result may be obtained as is readily understood. In order to determine which device A, B has to be used in each case the balance condenser K may be used. If by way of example the balance has been disturbed by that the capacity between the line parts 1 and 3 or 2 and 4 has been increased, or by that the capacity between the line brafiches 1 and 4 or 2 and 3 respectively has been reduced the sound in the telephone receiver will disappear in case the balance condenser K is turned to the right which again indicates that compensation may be brought about by actuating the device B for which purpose the operating lever 49 is turned downward. Then the wires are actuated by the rollers 37 so that the mutual positions of the wires are changed as required. The device B is held in operative position until the sound in the telephone receiver 27 disappears while at the same time the balance condenser takes up the middle position. The compensation may also take place without using the balance condenser which then is set in its middle position. By actuating the one and the other operating member 44 or 45 one may immediately ascertain by listening to the sound in the telephone receiver 27 which one of the devices A, B is to be used for the time being. Upon actuating the wrong operating member the sound in the telephone receiver is amplified whereas an actuation of the correct operating member brings about a weakening of the sound. By continuously supervising the electrical properties of the ready twisted portion of the cable during the twisting operation and by compensating disturbances in the balance in correspondence thereto a cable is obtained which is completely balanced in ready twisted condition or affords any desired degree of unbalance.

The wanted changes in the mutual coupling between the wires may also be brought about in another manner than by direct positive guidance of the wire in the manner above described. It is a known fact that also the pulling force in the wires being twisted exerts a certain influence upon the mutual positions of the wires in the ready twisted cable. This fact may be used for the present purpose in such a manner that for example the brake force applied to the different rollers 5, 6, 7, 8 is varied in correspondence to the changes in the balance occurring during the twisting procedure.

The coupling device K may be of different designs depending upon the electrical properties to be measured in the cable. Said device should however, preferably be adjustable in opposite directions from a middle position as in the shown embodiment in such a manner that it may bring about a temporary compensation of the unbalance upon using two actuating members A, B having opposite compensating actions.

Evidently the invention is not limited to quad twisted cables but may also be applied to cables where the line branches are twisted together to double lines or form duplex lines or the like. Further the invention may be applied also to other cables than telephone cables, such as telegraph cables.

Figure 3 shows a method of establishing an automatic compensation. The shearlike devices A and B in Figure 1 are then adapted to be actuated directly or indirectly by means of magnets or relays 56 and 57. In the example shown the relays 56 and 5'? control the circuits of solenoids 70 and '71, which when energized exert a pull in the wires 40 and 41, respectively. The circuits of the relays 56 and 57 include contact segments 58, 59 adapted to make contact with a contact arm 60 of the movable part of the balance condenser K. Said circuits are also controlled by a supervising relay 61 included in the Wheatstone bridge D between the points 23 and 24 and adapted to be deenergized when the cable is complete ly balanced and the balance condenser K takes up its middle position but which becomes energized as soon as the balance is disturbed or when the condenser K is turned in the one or the other 00 direction. The rotatable part 31 of the balance condenser is adapted to be oscillated about its middle position either manually or by means of a suitable driving device.

If the balance in the cable is disturbed the relay 61 will be energized, as mentioned above, when the rotatable part of the condenser takes up its middle position. Upon a continued movement of said part in the one or the other direction from middle position to a temporary position compen- 1' sation takes place at a certain angular position of the condenser the relay 61 then being deenergized and closes at its contact 62 a circuit through the one or the other of the relays 66, 6'7 and a battery 63. The one of said relays which then is ener- 1' gized attracts its armature and actuates the appertaining device A, B. At the same time the relay connects itself into a holding circuit over its contact 64 or 65 whereby the relay is held in operative position until the balance is restored. 9 When this takes place and the condenser reaches its middle position the relay 61 will be deenergized and the contact arm 60 will close a circuit for a relay 67.over a contact 66 said relay then being energized and interrupting the circuit at its com tact 68 for the one of the relays 56, 57 being operative for the time being. The relay 56 or 57 in question is thus deenergized whereby the device A or B again takes up its normal inoperative position. So long as the cable is completely bal- 130 anced the relays 56, 57 cannot be actuated because the relay 61 will then energize and open the contact 62 as soon as the condenser leaves its middle position and before the contact arm 60 makes contact with any one of the segments 58, 13 59, thus preventing closing of the circuits of the relays 56 and 57.

I claim:

1. In the manufacture of telephone cables a method of compensating cross-talk couplings 140 consisting in measuring the cross-talk couplings during the twisting operation and compensating for changes in the balance by changing the mutual positions of the cable conductors in the course of the twisting operation in accordance 145 with the variations ofthe couplings as ascertained by said measurements.

2. In the manufacture of telephone cables a method of compensating cross-talk couplings consisting in measuring the cross-talk couplings 150.

during the twisting operation and varying the guiding of the cable conductors in the course of the twisting operation so as to change the mutual positions of the conductors in accordance with the variations of the couplings as ascertained by said measurements.

3. The method as claimed in claim 2 applied to four-ply cables, in which the mutual positions of the conductors are varied by changing the distance between the conductors of each pair while maintaining substantially the relative angular position of the two pairs.

4. In a machine for the manufacture of tele-- phone cables an arrangement for compensating cross-talk couplings comprising a device for variably actuating the cable conductors during the twisting operation to change the mutual positions of the conductors, means for operating said device to change the mutual positions of the conductors and a measuring device connected to the conductors and adapted to indicate temporary deviations from the wanted coupling properties.

5. In a machine for the manufacture of telephone cables an arrangement for compensating cross-talk couplings comprising a rotating twist: ing nipple, adjustable stationary guides for guiding the cable conductors into said twisting nipple, means for operating said guides to change the mutual positions of the conductors, and a measuring device connected to the conductors and adapted to indicate temporary deviations from the wanted coupling properties.

6. An arrangement as claimed in claim 5, adapted for four-ply cables, in which the guides comprise two guiding members adapted to be set independently of one another and to actuate the conductors in two directions perpendicular to each other.

'7. An arrangement as claimed ,in claim 5, adapted for four-ply cables, in which the guides consist of two shears the legs of which are adapted to engage the conductors by means of rollers and which are arranged to actuate the conductors in two directions perpendicular to each other.

8. In a machine for the manufacture of telephone cables an arrangement for compensating cross-talk couplings comprising means for variably actuating the cable conductors during the twisting operation to change the mutual positions of the conductors, a measuring device connected to the conductors and adapted to respond to variations in the coupling between the conductors, and an operating device for said actuating means controlled by said measuring device so as to compensate automatically for variations in the coupling.

9. In a machine for the manufacture of telephone cables an arrangement for compensating cross-talk couplings comprising means for variably actuating the cable conductors during the twisting operation, a measuring device connected to the conductors and comprising a relay device (61) adapted to respond to variations in the coupling, and a variable coupling element (K) adapted to be set in opposite directions from a neutral position for the purpose of bringing about a temporary compensation of the unbalance and an operating device for said actuating means arranged under the control of said relay device and said coupling element so as to compensate automatically for variation in the coupling.

10. An arrangement as claimed in claim 9, in which the operating device comprises two members having opposite compensating actions and adapted to be operated by means ofjtwo corresponding relays the circuits of which are controlled by the relay device and the coupling element.

11. An arrangement as claimed in claim 9, in which the operating device comprises two members having opposite compensating actions which are adapted to be restored into inoperative positions by means of a relay (67) brought into operation when the balance is restored and the coupling element takes up its neutral middle position.

12. An arrangement as claimed in claim 9, in which the coupling element is operated so as to carry out an oscillating movementduring the twisting operation.

13. In a machine for the manufacture of telephone cables an arrangement for compensating 110 cross-talk couplings comprising means for variably actuating the cable conductors during the twisting operation, a measuring device connected to the conductors and comprising a relay device (61) adapted to respond to variations in the coupling, and a variable coupling element (K) adapted to be set in opposite directions from a neutral position for the purpose of bringing about a temporary compensation of the unbalance, an operating device for said actuating means arranged under the control of said relay device and said coupling element and comprising two operating members having opposite compensating actions, two operating relays for said operating members, a restoring relay for said operating 125 members arranged to operate when the balance is restored and the coupling element takes up its neutral middle position, and holding circuits for said operating relays controlled by said restoring relay. 130

AXEL ERIK HAETTN ER. 

